Low emissivity, high reflectivity insulation

Abstract

A multi-layer flexible insulation (I) comprises a series of layers which include a pair of closed-cell insulation sheets ( 10,12 ) made of multicellular plastic film (i.e. closed cell air bubbles or bubble-pack) and laminated on both sides of a thin white polyethylene film ( 14 ), a pair of aluminum foil layers or films ( 16,18 ) adhesively mounted on the outer surfaces of the bubble-pack insulation sheets ( 10,12 ), and a pair of thin clear polyester layers ( 20,22 ) provided on the outer surfaces of the aluminum layers. The aluminum layers ( 16,18 ) are vapor deposited on the polyester layers ( 20,22 ) and are assembled to the hot bubble-pack insulation sheets ( 10,12 ) while the latter are cooled. The bubble-pack sheets ( 10,12 ) are then adhered to the central polyethylene film ( 14 ) with a hot melt glue. If the polyester ( 20,22 ) is highly smooth, the aluminum ( 16,18 ) can be deposited thereon in a uniform state thereby providing a high reflectivity, low emissivity, laminate. The outer polyester coatings ( 20,22 ) also protect the aluminum layers ( 16,18 ) such as to prevent any aluminum from rubbing off the insulation (I) and also prevent the aluminum layers ( 16,18 ) from oxidizing. Furthermore, the polyester coatings ( 20,22 ) provide an hygiene barrier for the insulation (I).

What is claimed is:  
     
       1. A high reflectivity insulative material comprising an outer polyester sheet means, an insulation layer means, and an aluminum film means between an inner surface of said polyester sheet means and an outer surface of said insulation layer means, wherein said polyester sheet means has a melt point of at least approximately 400° F. thereby resulting in high smoothness such that said aluminum film means is substantially uniformly coated thereon, whereby said insulative material has a high reflectivity even with said polyester sheet means facing outwardly thereof, wherein said polyester sheet means, said insulation layer means and said aluminum film means form a laminate means, a pair of said laminate means being assembled symmetrically on each side of a plastic sheet means. 
     
     
       2. An insulative material as defined in claim  1 , wherein said polyester sheet means has an optical density of at least 3.10 at 75° F. 
     
     
       3. An insulative material as defined in claim  1 , wherein said polyester sheet means has a 48 gauge thickness. 
     
     
       4. An insulative material as defined in claim  1 , wherein said insulation layer means comprise a closed-cell insulation. 
     
     
       5. An insulative material as defined in claim  1 , wherein said aluminum film means has a thickness of approximately 250° A. 
     
     
       6. An insulative material as defined in claim  1 , wherein said polyester sheet means has an optical density of at least 3.10 at 75° F. and a 48 gauge thickness. 
     
     
       7. An insulative material as defined in claim  1 , wherein said plastic sheet means is made of polyethylene. 
     
     
       8. A method for producing a high reflectivity insulative material, comprising the steps of: 
       a) providing and heating a polyester film having a melt point of at least approximately 400° F.;  
       b) depositing a coating of aluminum on the heated polyester film; and  
       c) providing a thermally insulative layer on said aluminum coating opposite said polyester film;  
       wherein said polyester film, said insulative layer and the aluminum therebetween form a laminate means, a pair of said laminate means being assembled symmetrically on each side of a plastic sheet.  
     
     
       9. A method as defined in claim  8 , wherein said plastic sheet is made of polyethylene. 
     
     
       10. A method as defined in claim  8 , wherein in step (b), said aluminum is vapor deposited on said polyester film and wherein said coating of aluminum has a thickness of approximately 250° A. 
     
     
       11. A method as defined in claim  8 , wherein in step (b), said aluminum is vapor deposited on said polyester film. 
     
     
       12. A method as defined in claim  8 , wherein said polyester film has an optical density of at least 3.10 at 75° F. 
     
     
       13. A method as defined in claim  8 , wherein said polyester film has a 48 gauge thickness. 
     
     
       14. A method as defined in claim  8 , wherein said coating of aluminum has a thickness of approximately 250° A.